There is a need to quickly determine the weight of an object or a human individual set on a weighing device or scale.
However, in weighing scales, there are many unwanted transients and frequency components, like vibrations which occur when an object/person comes to be placed on the platform, or like transients coming from small movements made by the person standing on the scale. For example, a baby or young child is prone to wriggling when set on a baby/child scale and this generates noisy additions to the weight.
Another type of disturbance exist, sometimes at home, but more often in the manufacturing factory where the weighing device is tested and calibrated, like for instance vibrations coming from nearby machinery (e.g. in buildings: lift, air-conditioning unit, vibratory environment in workshops: stamping press, forklift, machining units, etc. . . . ),
It is thus not easy to recover the actual weight from such a noisy signal.
Low pass filtering gives good results to eliminate such transients and frequency components. However, it requires more time to converge toward the actual weight of the object/person present on the scale. Examples of low pass methods include multiple average method as taught for instance in document U.S. Pat. No. 5,062,492. The response time is increased by the various averaging processes.
Therefore, there remains a need to propose a weighing method and device which can provide a reliable result faster than known devices in such noisy conditions. But decrease of response time must not be detrimental to accuracy.
Besides it is another constraint to run the weight measurement process with a low electrical consumption and low computing resources.
Although the present invention is particularly directed to an electronic scale (‘bathroom scale’ or ‘baby scale’), the invention is applicable to any weight measuring device which indicate a calculated value from a rather noisy signal.